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SGM3138 6-Channel Charge Pump White LED Driver with Low Dropout Current Source
GENERAL DESCRIPTION
The SGM3138 is a high performance white LED driver. It integrates current sources and automatic mode selection charge pump. The part maintains the high efficiency by utilizing a 1×/1.5× fractional charge pump and low dropout current sources. The small equivalent 1× mode open loop resistance and ultra-low dropout voltage of current source extend the operating time of 1× mode and optimize the efficiency of Li-ion battery in white LED applications.
The SGM3138 supports up to 6 white LEDs and regulates a constant current which the initial value can be set by an internal resistor. The part implements a 4-bit DAC for brightness control. Users can easily configure the LED current from 1.25mA to 20mA by a serial pulse. The dimming of white LEDs current can be achieved by applying a pulse signal to the EN/SET pin. There are totally 16 steps of current could be set by users. The operating voltage range is 2.7V to 5.5V. Internal soft-start circuitry effectively reduces the in-rush current while both start-up and mode transition.
FEATURES
Input Voltage Range: 2.7V to 5.5V Drives Up to 6 LEDs at 20mA Each One Single Wire Interface 16-Step Brightness Control High Efficiency by Fractional Conversion with
1× and 1.5× Modes Switching Frequency: 1MHz Regulated Output Current with ±5% Matching Internal Soft-Start Limits Inrush Current Low Input Ripple and Low EMI Over-Current and Over-Temperature Protection Under-Voltage Lockout with Hysteresis Available in Green TQFN-3×3-16L Package
APPLICATIONS
Mobile Phone, DSC, MP3 White LED Backlighting LCD Display Supply
The SGM3138 is available in Green TQFN-3×3-16L package and is rated over the -40℃ to +85℃ temperature range.
SG Micro Corp www.sg-micro.com
REV. A. 4
SGM3138
6-Channel Charge Pump White LED Driver with Low Dropout Current Source
PACKAGE/ORDERING INFORMATION
MODEL
ORDER NUMBER
SGM3138 SGM3138YTQ16G/TR
PACKAGE DESCRIPTION
TQFN-3×3-16L
SPECIFIED TEMPERATURE
RANGE
-40℃ to +85℃
PACKAGE OPTION
Tape and Reel, 3000
MARKING INFORMATION
3138TQ
ABSOLUTE MAXIMUM RATINGS
VIN to GND……………………...……...….....….….. -0.3V to 6.0V The Other Pins to GND…………………..……....….. -0.3V to VIN Power Dissipation, PD @ TA = 25℃ TQFN-3×3-16L………………………………..…………..…1.47W Storage Temperature Range...………….....…...-65℃ to +150℃
Junction Temperature………………………..……………...150℃
Operating Temperature Range...…………...……-40℃ to +85℃ Lead Temperature (Soldering 10 sec) …………………………………..……………....….….…….. 260℃ ESD Susceptibility HBM…………………………………………..….…………...2000V MM………………………………………….…...………..……200V
NOTE: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
CAUTION
This integrated circuit can be damaged by ESD if you don’t pay attention to ESD protection. SGMICRO recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
SGMICRO reserves the right to make any change in circuit design, specification or other related things if necessary without notice at any time. Please contact SGMICRO sales office to get the latest datasheet.
SG Micro Corp www.sg-micro.com
2
SGM3138
6-Channel Charge Pump White LED Driver with Low Dropout Current Source
PIN CONFIGURATION (TOP VIEW)
EN/ N.C. SET AGND VIN
16 15 14 13
LED6 1
12 C2N
LED5 2 LED4 3
GND
11 C1N 10 C1P
LED3 4
5
67
9 C2P 8
LED2 LED1 PGND VOUT
TQFN-3×3-16L
PIN DESCRIPTION
PIN
NAME
I/O
FUNCTION
1, 2, 3, 4, 5, 6
LED6-LED1
I
Current Sink Input. Connect the cathode of the white LEDs to these inputs.
7
PGND
- Power Ground.
8
VOUT
O Connect the output capacitor and the anode of the LEDs to this pin.
9
C2P
- Positive Terminal of Bucket Capacitor 2.
10
C1P
- Positive Terminal of Bucket Capacitor 1.
11
C1N
- Negative Terminal of Bucket Capacitor 1.
12
C2N
- Negative Terminal of Bucket Capacitor 2.
13 VIN I Supply Voltage Input.
14
15
16 Exposed
Pad
AGND EN/SET
N.C. GND
- Analog Ground.
I
LED1 to LED6 Enable (Active High) and Dimming Control. Connect to GPIO pin of MCU.
- No Internal Connection.
- Exposed pad should be soldered to PCB board and connected to GND.
SG Micro Corp www.sg-micro.com
3
SGM3138
6-Channel Charge Pump White LED Driver with Low Dropout Current Source
ELECTRICAL CHARACTERISTICS
(VIN = 3.6V, EN/SET = VIN.